Evaluation of the Functional Properties of Extruded Snacks from Cassava and Bambara Groundnut Blends in Kwara State

Bambara groundnut (Vigna subterranea) is a drought-tolerant, protein-rich legume widely cultivated in North Central Nigeria but underutilised in processed food applications. This study formulates and evaluates extruded snacks from blends of cassava flour and Bambara groundnut flour at ratios of 90:10, 80:20, 70:30, and 60:40, processed in Ilorin, Kwara State. Extrusion was conducted using a single-screw extruder at barrel temperatures of 120, 140, and 160 degrees Celsius. Extrudate quality was characterised by expansion ratio, bulk density, specific mechanical energy, breaking strength, colour, and water absorption index. Proximate composition, amino acid profile, and in vitro protein digestibility were determined. Consumer sensory testing was conducted by 45 participants at a community centre in Ilorin. Results showed that the 20 percent Bambara groundnut substitution at 140 degrees Celsius produced the best combination of expansion ratio, protein content, and sensory acceptability. Protein content increased from 3.2 percent for 100 percent cassava to 11.7 percent for the 20 percent blend. In vitro protein digestibility was 78 percent for the optimised formulation. The study draws on recent legume-cereal extrusion literature and contributes to the utilisation of underexploited legumes in West African food processing. Findings are applicable to snack food manufacturers and nutrition intervention programmes in Kwara State. Keywords: extrusion, Bambara groundnut, cassava, functional properties, Kwara State